That’s because there weren’t multiple people around to write down what they saw. You’re confusing paleontology and history. They have very different standards for proof.
There are tons of historical figures for whom we have no physical evidence. But we have tons of written evidence from people who all experienced those people.
I’m pretty sure without the fossilised bones we would think dinosaurs weren’t a thing
Bones prove you existed.
But the absence of bones does not mean that you didn’t.
That’s because there weren’t multiple people around to write down what they saw. You’re confusing paleontology and history. They have very different standards for proof.
There are tons of historical figures for whom we have no physical evidence. But we have tons of written evidence from people who all experienced those people.